Period hit Downton Abbey triumphed in the battle of the dramas last night with double the audience of spy series Spooks.

The return of the ITV1 show pulled in an average of 9.3 million viewers, against the 4.6 million audience for the BBC1 programme, which began its final run last night.

But Downton proved to be something of a turn-off for some viewers as it lost 1.6 million viewers from the start to the finish of the 90-minute episode.

The ITV series - which follows the Crawley family as Britain heads into the First World War - had been expected to triumph when the two shows went head to head.

Downton - which won two Emmys last night - became a runaway success during its series, screened last year, regularly pulling in more than 9 million viewers.

Last night's episode also benefited from a huge audience for The X Factor with 12 million tuning in for the climax of the contest.

A BBC spokesman said: "Downton and Spooks are very different shows and offer a real alternative for audiences. This is the last ever series of Spooks and we wanted to celebrate this and make it a special event for viewers in the Sunday 9pm slot.

"It is not unusual for drama to go up against drama here, for example, David Tennant's Single Father did last year and ITV's Vera was up against BBC1's Exile earlier this year."